---
type: claim
domain: space-development
description: "About 100 known NEAs need less delta-v than a lunar landing (4-5 km/s vs 6 km/s); from Mars orbit approximately 100,000 Main Belt asteroids become accessible at less than 5 km/s"
confidence: likely
source: "Astra, web research compilation February 2026; orbital mechanics literature"
created: 2026-02-17
depends_on:
- asteroid mining economics split into three distinct business models with water-for-propellant viable near-term and metals-for-Earth-return decades away
supports:
- asteroid mining and orbital habitats should be prioritized over planetary colonization because gravity wells are the binding constraint on opening the solar system to humanity
reweave_edges:
- asteroid mining and orbital habitats should be prioritized over planetary colonization because gravity wells are the binding constraint on opening the solar system to humanity|supports|2026-04-04
sourced_from:
- inbox/archive/2026-02-17-astra-space-asteroid-mining.md
---

# Ten percent of near-Earth asteroids are more energetically accessible than the lunar surface with some requiring less delta-v than a soft Moon landing

In space, distance matters less than delta-v -- the velocity change needed to transfer between orbits, which determines fuel requirements and mission cost. Approximately 10% of near-Earth asteroids are more accessible (lower delta-v) than the Moon. About 100 known NEAs require less delta-v than a soft lunar landing: 4-5 km/s versus 6 km/s for the lunar surface. Optimal targets are "Arjuna" class asteroids occupying very Earth-like orbits -- low inclination (under 10 degrees), semi-major axis near 1.0 AU, small eccentricity.

This accessibility math has a profound implication: for certain missions, reaching an asteroid is easier than reaching the Moon. The reason asteroid mining is harder than lunar mining is not energetics but rather the immaturity of proximity operations, anchoring, and extraction technologies at near-zero gravity. The physics favors asteroids; the engineering currently favors the Moon.

From Mars orbit, the calculus shifts dramatically. Approximately 100,000 known Main Belt asteroids become accessible at less than 5 km/s delta-v. This suggests a future where Mars orbit serves as a staging base for industrial-scale asteroid mining of the Main Belt -- a fundamentally different architecture than Earth-based operations targeting NEAs. The 30-year projection should account for this staging option: by 2056, early Mars orbital infrastructure could be positioning for Main Belt mining operations that dwarf anything accessible from Earth orbit.

## Evidence
- ~10% of NEAs are more energetically accessible than the lunar surface
- ~100 known NEAs require 4-5 km/s delta-v vs 6 km/s for lunar landing
- Arjuna-class asteroids in Earth-like orbits are optimal near-term targets
- ~100,000 Main Belt asteroids accessible at <5 km/s from Mars orbit

## Challenges
Delta-v accessibility does not account for transfer time, launch windows, or mission duration. Many low-delta-v NEAs have narrow launch windows and multi-year mission profiles, making them logistically harder than the Moon despite lower energy requirements. The Mars staging concept is decades away and depends on Mars infrastructure that doesn't exist.

---

Relevant Notes:
- [[asteroid mining economics split into three distinct business models with water-for-propellant viable near-term and metals-for-Earth-return decades away]] — NEA accessibility determines which asteroids are viable for near-term water extraction
- [[asteroid mining technology readiness drops sharply after prospecting with anchoring at TRL 2-3 and zero-gravity refining at TRL 1-2]] — physics favors asteroids but engineering favors the Moon
- [[the Moon serves as a proving ground for Mars settlement because 2-day transit enables 180x faster iteration cycles than the 6-month Mars journey]] — lunar proximity advantage offsets asteroid energy advantage for development iteration

Topics:
- [[space exploration and development]]